The Centers for Disease Control and Prevention (CDC) issued new guidelines Saturday reported serious allergic reactions to the coronavirus vaccine.
The agency said it had recently “learned of reports” of some people experiencing severe allergic reactions after being vaccinated. The service defined a “severe reaction” as a reaction in which a person must be treated with epinephrine or require hospitalization.
The CDC said people with severe allergic reactions after the first dose should not receive the second injection.
Those who have had severe allergic reactions to any ingredient in a COVID-19 vaccine should not receive that particular vaccine.
The agency also advises those who have had severe allergic reactions to other vaccines or therapies to see their doctor before getting vaccinated. However, people with a history of severe allergic reactions unrelated to vaccines or injectable medications can still be vaccinated, the CDC said.
The guidelines come after the Food and Drug Administration (FDA) said it was investigating five serious reactions to Pfizer’s vaccine reported this week. Two responses were reported in Alaska, and the others have been reported in other states.
Peter Marks, who heads the agency’s Center for Biologics Evaluation and Research, told reporters the agency wasn’t sure what triggered the reaction, but said a chemical called polyethylene glycol, which is present in Pfizer and Moderna’s coronavirus vaccine, perpetrator. ”
The agency said Friday that people with a history of severe allergic reactions to any part of the vaccine should avoid getting vaccinated.
The UK medicines and healthcare products regulator warned earlier this month that people with a “significant” history of allergic reactions should avoid the Pfizers vaccine, after two people reported side effects.